3Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine; Kharkіv National University of Radio Electronics of the Ministry of Education and Science of Ukraine, Kharkiv,Ukraine

The Ukrainian national navigation service is supposed to be based on the signals from the global navigational GPS and GLONASS systems and the geostationary INMARSAT-3 satellites. The differential navigation in Ukraine will be provided by a multifunctional network of reference stations which is supposed to be integrated into the European segment of the international GNSS-1 system. The basis of the Ukrainian differential system will be a ground-based segment including the main network of regional reference stations (RS) network and local RS networks. The regional RS network (12 RS) will be built on the principles of wide-area navigation using the complex processing of code and carrier-phase LI, L2 observations. The observations will be transmitted to the European GNSS-1 processing data centre for the formation and transmission of DCI and integrity through the INMARSAT-3 geostationary satellite. The local RS networks will be used to solve the navigation service problems in the areas of intense transport movement. Regional and local RS networks will operate jointly. The possibilities of DCI transmission through a national geostationary communication satellite with a board navigation transponder are also discussed. The injection of this satellite into orbit will give us a possibility of increasing the reliability and potentialities of GNSS-1.